The electroactive cathode in a conventional polymer electrolyte-based battery is composed of a solid-state material such as a transition metal oxide or a transition metal chalcogenide. Examples of such materials are the oxides, V.sub.2 O.sub.5, V.sub.6 O.sub.13, LiCoO.sub.2, LiMn.sub.2 O.sub.2, and the chalcogenides TiS.sub.2, MoS.sub.2, NbSe.sub.3, and MoS.sub.3. A polymer electrolyte-based lithium battery cell utilizing a solid-state cathode material is fabricated by sandwiching a polymer electrolyte film between a Li foil anode (negative electrode) and the said, electroactive, solid-state cathode (positive electrode) that has been fashioned in to a composite electrode. Typically, the latter is fabricated by rolling, pressing or extruding a mixture of the solid-state cathode material, the polymer electrolyte and an electronic conductor (usually a high surface-area carbon) into a thin film on a metal foil, usually Al. The polymer electrolyte film placed between the composite cathode and the Li anode serves both as the separator in the battery and the medium through which Li ions are transported from the Li anode to the cathode during battery discharge. The reaction at the solid-state cathode during battery discharge involves the insertion of Li ions into crystal lattice sites in the cathode material with the positive charge on the Li being compensated for by electrons injected into the conduction bands of the cathode material from the external circuit. During recharge of the battery the opposite process takes place. These cathode reactions are illustrated in equation 1 ! using TiS.sub.2 as the example. ##STR1## Reactions involving other Li inserting cathode materials are well-known to those skilled in the art.
Vassort et. al. (in Proceedings of the Symposium on "Primary and Secondary Ambient Temperature Lithium Batteries", J. P. Gabano et. al., eds., The Electrochemical Society, 10 South Main Street, Pennington, N.J. (PV88-6, 780 (1988)), have described polymer electrolyte-based Li/TiS.sub.2,and Li/MnO.sub.2 cells containing polymer electrolytes composed of Li salt (e.g., LiCClO.sub.4 or LiCF.sub.3 SO.sub.3) complexes of poly(ethylene oxide). Abraham and Alamgir have reported (in Solid-State Ionics, 70/71, 20 (1994)) on Li/LiMn.sub.2 O.sub.4 cells containing polymer electrolytes composed of polyacrylonitrile (PAN), propylene carbonate (PC), ethylene carbonate (EC) and a Li salt (e.g., LiClO.sub.4, LiAsF.sub.6, LiN(SO.sub.2 CF.sub.3).sub.2 or LiPF.sub.6). ). Alamgir and Abraham have also disclosed in U.S. Pat. No. 5,252,413, solid polymer electrolyte-based Li batteries in which the cathode active material is TiS.sub.2, V.sub.6 O.sub.3, FeS.sub.2, LiNiO.sub.2, LiCoO.sub.2 or LiMn.sub.2 O.sub.4 and the polymer electrolyte is composed of poly(vinyl chloride), an aprotic organic solvent (or a mixture of such solvents) and a Li salt (e.g., LiClO.sub.4, LiBF.sub.4, LiAsF.sub.6, LiCF.sub.3 SO.sub.3 ; LiPF.sub.6, or LiN(SO.sub.2 CF.sub.3).sub.2).
In this patent application, we disclose a polymer electrolyte-based Li battery which is unlike any of the polymer electrolyte-based batteries known to-date. This battery has oxygen (O.sub.2) gas as its electroactive cathode, and the battery discharge reaction involves the reduction of oxygen to form lithium oxide.